How nice that you've created some wonderful family traditions!
That's probably a great thing to add to piecing. I realized during the divorce that there aren't a lot of photos of my husband and I together (I'm the family photographer!). One thing I'm really going to try and do is take more photos of me and my husband together, or both of us with the kids, and put them around the house (even dig up a couple of old wedding photos!).
Even through your in-laws are great, are there other extended family members who you might have to see during the holidays who might be asking questions about your marriage? I'm probably worrying about this more than I should. Most people are usually pretty tactful about stuff like this. I just worry about the few who tend to have a little too much "holiday cheer."
In fact, I remember about 6 months ago when my divorce started, I went to my husband's aunt and uncle's anniversary and his sister had a few drinks too many and started telling me about all the terrible things my husband (her brother) was saying about me and how I should find someone who makes a lot more money and will appreciate me more. Although she meant well and was trying to be nice and supportive, it probably wasn't the best place for that. Also, I'm not sure how much my kids heard.
I just worry because holidays can be a funny time and piecing is hard enough without nutty extended family interference. Also, my sitch was more than just a little bit of marital difficulty. It was 6 months of separation and divorce. I think everyone believed it was over (in fact they all went to Hawaii together over the summer without me or the kids!).
Oh well, I probably need to quit worrying about this. ...
There is no arriving, ever. It is all a continual becoming.